Brake mechanism for vehicle road wheels



BRAKE MEGHANISM FOR VEHICLE ROAD WHEELS Filed Jan. 19, 1940 INVENTOR 37 BYQQM i Z 2ATTOREEY drawing wherein:

Patented Aug. 19, 1941.

NT OFFICE BRAKE MECHANISM FOR. VEHICLE ROAD v WHEELS Ferdinand Forsche, Stuttgart, Germany, assigner to Dr. ing. h. c. F. Porsche K.G., Stuttgart Zuenhausen, Germany, a company oi.' German? Application January 19, 1940, Serial No. 314,586

Germany July 13,1939

13 claims.

The present invention relates to improvements in brake mechanism for vehicle road wheels.

It is an object of the present invention to A provide a brake mechanism which may bereadily adjusted.

To that end it is an object to provide means for temporarily holding the brake operating sure that after brake operation the brake shoes I and 2 will be withdrawn from contact with the brake drum (shown in dotted lines at 25) into the brake released position.

The brake shoes are located in 'a definite position by means of the bolts 26 and 21I carried by members in a deiinite position so that the means for operating the brake operating element, such as a cable connected for operation by the foot pedal, may be conveniently connected up.A

f It is Aanother object of the invention to provide a temporary holding means so constructed and arranged' that it is impossible to place the vehicle in driving condition without first removing the temporary holding means. In this way, accidents are avoided which might otherwise occur due to inability to apply-the brakes.

It is another object of the invention to improve generally brake means for power vehicles.

Other objects will appear from the following description of an illustrative embodiment of the invention taken together `with the attached Fig. 1 oi said drawing illustrates in elevation one form' the invention may take, the brake drum having been removed; and

Fig. 2 is a horizontal cross-section o! the brake mechanism taken along the line II-II 'of Fig. 1.

As shown in the drawing, the brake is provided with two brake shoes I and 2, provided with brake linings 3 vand 4, respectively. I'he lower ends oi.' the brake shoes bear upon and are guided by `supporti; li carried by the brake plate 3, whereas, the upper end cooperates with an arrangement for spreading the brake shoes and thereby causing application oi' the brake. This occurs by means of arr-angle lever 1 to arm 3 oi' which a cable 3 i'or operating the brake'is connected by lmeans of a pivot bolt I3. The lever 1 is pivoted by bolt I2 to the brake shoe 2 at the point Il and its other arm I3 is connected with brake shoe I by means of the link or strut lI4 by means of the pivot bolts I3 and I3.

For this purpose, rollers I1 and Il are preterwhich bolts have notches which receive a race formed upon the projections I3 and 2l ot the brake plate 3, thereby providing guide means not only for the upper end of the brake shoes I and 2 but also for the 'angle lever 1 and the connecting strut I4. Preferably a leafl spring 22. held in place for example by means of the cotter pin 2|, serves also to assure a definite location of the brake shoes. Retracting springs 23and 24 aslably provided upon the pivot bolts I2 and I3,`

the shoes I and 2, respectively, which-bear into V-shaped notches 28 and 29 upon the brake plate B.

The connecting'strut I4 is shown as having a U-formed cross-section between whose side walls 30, 3|, thearm 8 of the angle lever 1 lies. In brake released position, this arm may come to rest against the web 32 of the strut I4 Ias appears in Fig. 2. By means of this construction it is possible to eliminate the danger' thatby stretching of the operating cable 3 the arm l might collide with the brake drum 25, or even prevent its rotation if it is provided with` ribssuch as indicated at 33. The two side pieces 30 and 3| of the strut I are provided with extensions 34, 35 which cover substantially the path traveled by the pivot bolt I0, serving for connection with the tension cable 3, during actuation of the brake. Therefore, the connec-ting bolt I0 during v.assembly oi the parts is merely pushed into place and thereupon when the arm 8 is swung back between the side pieces 3l! and 3| and their extensions 34, 35, the bolt lines in Figs. l and 2, is inserted through said opening, the angle lever 1 is held in its ineffective position (due to the engagement of the bolt 31 therewith or with a recess therein as shown) and -the brake shoes I and 2 are locked against operation. The adjustment of the tension cable 3 may now be readily eiected as by adjusting the position oi 3 by adjusting the nut 40.

The locking bolt is preferably formed as an ,arm oi an L-shaped member consisting of a round rod or wire. The locking bolt may be inserted, assuming 'that the brake drum 231s in place, by pushing it through a closable opening 33 in the brake drum' and one of its ends iny.

serieu into the 'bore se or the strut link yas is shown in dotted lines. It willbe noted that the holding bolt is so constructed that in the event its removal is forgotten, it will be impossible to.

its sheath 39 relative to the cablev assemble' the wheelI upon the hub, whereby the utilization o'f the vehicle with ineffective brakes isprevented.

The expression fangle. lever as applied to the l lever 1 is not to be understood as restricting it to the form shown, and it is therefore pointed out that the angle between the arm to which the cable is attached and the operating arm may be anywhere from to 180.

It is furthermore to be 'understood that instead of an operating cable an operating linkage of any type might be employed.

It will be noted that the brake shoe spreading members are arranged for movement in a plane which is generally parallel to the axis of the road wheel. This has the desirable effect thatu the operating connection such as the cable 9|, may extend generally parallel to said axis, a most desirable construction.

Having described an illustrative embodiment of the invention, it is pointed out that various changes and modifications therein may be made without departing from the invention as set forth in the following claims.

. I claim:

1. In brake mechanism, at least one brake shoe,

operating means therefor, connecting means for actuating said operating means and means for temporarily locking said operating means in a .fixed position, whereby said connecting means may be readily adjusted, said temporary locking means comprising a bolt passing through elements of said Ioperating means and having an extension which extends outwardly and prevents the assembly of the road wheel, whereby the wheel may not be assembled and the vehicle operated when the locking bolt is in effective position.

4. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading means and means for temporarily locking said spreading means in in effective position, whereby said connecting means may be readily adjusted.

5. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading means and means for temporarily locking said spreading means in ineffective position, whereby said connecting means may be readilyA adjusted, said temporary locking vmeans belng'so constructed and arranged that the road wheel may not be assembled in place when the locking means is effective.

6. In` brake mechanism, a pair of brake shoes,

l spreading means therefor, connecting means for actuating said spreading means comprising a lever bearing against Aone of said brake shoes and a strut bearing against said-lever and against the other'brake shoe and means for temporarily locking said spreading means in a xed position comprising a bolt passing through said. lever and said strut, whereby said connecting means may be readily adjusted.

7. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading means comprising a lever bearing against one `of said brake shoes and a strut bearing against said lever and against the other brake shoe and means for temporarily locking said spreading means in a fixed position comprising a bolt passing through said lever and said strut, whereby said connecting means may be readily adjust-ed, said bolt being formed with a-n extension which serves to prevent operation of the vehicle when said bolt is in position.

`8. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading -means comprising a lever bearing against one of said brake shoes and a U-shaped strut bearing against said lever and against the other brake shoe and-serving' to receive said levervbetween its walls, means for attaching said connecting meansto said lever including a bolt, said strut being-so formed that said bolt is located between said walls in all positions of said lever so that the bolt is held in place thereby.

9. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading means comprising a lever bearing against one of said brake shoes and a U-shaped strut bearing against said lever and against the other brake shoe and serving to receive said lever between its walls, means fo'i' attaching said connecting means to said lever including a bolt, said strut being so formed that said bolt is located between said walls in all positions of said lever so that the bolt is 4held in place thereby, and means for temporarily locking said spreading means in a fixed position comprising a locking bolt passing through said lever and the walls of said strut, whereby said connecting means may be readily adjusted.

10. In brake mechanism, a pair of brake shoes,

spreading means therefor, connecting means for actuating said spreading means comprising a lever bearing against one oi' said brake shoes and a U-shaped strut bearing against said lever and against the other brake shoe and serving to receive said lever between its walls, the strut andv lever being so formed that the connecting web of said U-shaped section serves to limit movement of the lever relative to the strut toward the brake released position.

1l. In brake mechanism, a pair of brake shoes, spreading means therefor, connecting means for actuating said spreading v'means comprising a lever bearingv against one of said `brake shoes and a U-shaped strut bearing against said lever lever bearing against one of said brake shoes and a U-shaped strut bearing against said lever and against the other brake shoe and serving to 'receive said lever betweenl its walls, the strut and lever being so formed that the connecting web of said U-shaped section serves to limit movet ment of the lever relative to the strut toward the brake released position, and means for temporarily locking said lever in brake released position whereby said connecting means may be readily adjusted, said temporarylocking means comprising a bolt passing through said lever and through the side walls of said strut.

13. In brake mechanism, a pair of brake shoes,

spreading means therefor, connecting means for m actuating said spreading means comprising a lever bearing against one of said brake s'hoes and a U-shaped strut bearing against said lever and against the other brake shoe and serving to receive said lever between its walls, the strut and lever being so form'ed that the connecting web of 1 said U-shaped section' serves to limit movement of the lever relative to the strut toward the brake released position, and means for temporarily locking said lever in brake released position whereby said connecting means may -be vreadily adjusted, said temporary locking means comprising a bolt passing through said lever and through the side walls of said strut and having an extension which extends outwardly and prevents the assembly of the road wheel.

FERDINAND PORSCHE. 

